Maragadha Naanayam (transl. Emerald Coin or The Killer Diamond) is a 2017 Indian Tamil-language fantasy comedy film written and directed by ARK Saravan in his directorial debut. The film stars Aadhi and Nikki Galrani while Anandaraj, Munishkanth, Daniel Annie Pope, Mime Gopi, and Kota Srinivasa Rao play supporting roles. The music was composed by first-timer Dhibu Ninan Thomas with cinematography by PV Shankar and editing by Prasanna GK.

The film was released on 16 June 2017 in Tamil and Telugu languages, the latter titled Marakathamani. On 27 July 2023 Director ARK Saravanan confirmed the sequel 'Maragadha Naanayam 2'.